Fuel-feeding apparatus.



T. 'A. EDISON.

FUEL FEEDING APPARATUS. APPLICATION 211.111) NOV. 39, 1907.

Patented Aug. 11, 1914,

LMMAQA.

2 SHEETS-SHEET 1.

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T. A. EDISON. FUEL FEEDING APPARATUS. APPLICATION FILED NOV. 29. 1907.

1,106,444. Patented Aug. 11,1914;

2 SHEETS-SHEET 2.

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, resident of Llewellyn Park, Orange, county V 5, of Essex, and State ofNewJersey, have inr no L cense,

I Specification of Letters latent. Application filed November 29, 1307.Serial No. 404,215.

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Patented dugrilil, 191%.

T6 whorl; it may-concern: Be it known that I, THOMAS ALVA EDI- son, acitizen of the United States, and a vented certain new and usefulImprovements in Fuel-Feeding; Apparatus, of which the following is adescription.

vlily invention relates to animproved ap paratus for feeding fineorpulverized fuel,

and the invention has been especially .de

signed, and. has been successfully used, for

feeding pulverized coal into rotary. cement IIS.

object is to produce anapparatus by means iof-which fine or pulverizedfuel may be fed ina compact stream within a rotary kiln or other heatingchamber in an efiective manner and at leiw cost. At the present time inthe-operation of rotary cement kilns,

it is the generalpractice to force'the pulverized coal into the kilnwith ablast ofair amounting'only to-a small proportion of thatnecessaryfor complete combustion, the balance of the air being drawn into thekiln by the inductive effect of the blast and by the draft created bythe stack; and with the best practice the largebulk of combustion airwhich is thus drawn into the kiln surrounds the central core ofpulverized fuel as an inclosing envelop. This practice of feedingpulverized fuel to a cement kiln is objectionably expensive. Forexample, in the operation of several standard 150 foot Edison kilns,e'ach equipped with two blast nozzles, I found that air compressorsofsubstantially horsepower for each kiln were I necessary toeifect theproper feed, whereas,

The projecting device in its preferred form comprises a suitable casingin which is r0- tatably mounted, a series of radial arms, carryingwingsfwhich engage the fuel particlesl and project them centrifugallyinto a kiln,

such arms beingrotated within the casing at an enormous surface.veloc1ty.

Inorderthat the invention may be better 1 understood attention isdirectedto the accompanying drawings, forming part of thisspecificationfand in which- T Fig re, Irepresents a front :elevation,partly in section, showing a rotary. kiln and the cooler,andillustrating the use of two projecting devices for feeding fuel tothe kiln; Fig. 2, alongitudinal.sectional view of the same showing meansfor driving the feeding devices at different speeds; and Fig. Elanenlarged cross-sectional view of one of the feeding devices. v

' .In all of these views, corresponding parts are rep-resented by thesame numerals of reference. 1 I

I -The rotary kilnl, thestationary chamber 2, into which it leads,.andthe cooler 3 for receiving the clinkered material from the kiln, areall, of. well-known construction. Suitable means (not shown) are.employed for feeding unburned cement material to the upper end ofthekiln. At the front of the kiln is the usual platform 4 on which theoperator may stand for observing the operition of the kiln. Mounted uponthis platiorm is a suitablerstandard 5,.carrying the two projectingdevices 6, from each of which leads a nozzle 7. These nozzles, as willbe ebvious,,are arranged on either. side of the llongitudinal axisof'the kiln. Each projectitng device comprises a suitable two partcasing (see Fig. 3) bolted together, one section being formed with anentrance passage 8 through which'the fuelenters the casing,

Extending around the interior of the casing is a removable ring 9,having an opening,

passage to-the nozzle 7, as will'be understood, and made of chilled ironor other very hard material. Practically all of the wear within thecasing will be confined to this removable ring, which can be taken outand replaced when worn. Mounted in each casing is a shaft 10, carried insuitable bearings'11-1l, outside of the casing and driven by a pulley 12from any suitable source of power. The shaft 10 carries a spider 13diameter of the plates is twenty-four inches and rotate the shaft atfrom 2500 to 3000 revolutions per minute, giving a surface. velocity tothe particles of upward of 15,000 'feet per minute. With a feedingdevice ofthis size and operated at'this speed, I find it possible tofeed as much coal in as effective a manner as can be done under presentconditions with an expenditure of horsepower for operating an aircompressor. The pulverized fuel is supplied to each feeding device byany suitable mechanism; I illustrate a bin 15, containin thefinelypulveramount of fuel supplied to each feeding ized fuel, and connecteatits lower end with one or more screw conveyers 16, for delivering thefuel to a pipe 17 connected with the assage 8. Any suitable mechanismcan. e employed for-regulating tihe evice, for instance, the shaft ofeach 0 the conveyers 16 may be rovided with a fric tion wheel 18, with wich a friction wheel 19 engages, mounted on a shaft 20. By varyin theposition of each friction wheel 19 wit reference to the center 'of the00- operating friction wheel 18, .the speedof the conveyer will beregulated and the supply of fuel in this way-may be controlled, as willbe obvious. wheels 19 with respect to the wheels 18 may be regulated byany convenient means, as for example, by means of the shifting lever 22pivoted at 23 and carrying a pin 24 at its lower end, engaging betweenshoulders 25 and 26 on the shaft 20. The speed of rotation of each ofthe feeding devices may be the same, so that two streams 'ofpulverizedfuel will be fed at the same velocity into a kiln (as shown in Fig. 1),butpreferably, the speed of one feedin device is hi her than that of theother, so that the com us tion zones as formed by the burning fuel, willoverlap so as-to thereby form an extended area in which the clinkeringoperation takes place. A- construction for accomplishing this lastresult is shown in Fig. 2 in full and dotted lines, pulleys 12 ofthesame size being directly connected to the shafts of the feedindevices and being driven by belts 27 an 28 respectively, passing overpulleys 29 and 30 of different sizesfixed todriving shaft 31.Ordinarily, I provide a small air vent 21 above-the p1pe'17, to preventthe suction of the fans or wings 14 from drawing the pulverized fuelpast the conveyer-16, but the amount of air which thus enters thefeeding device is negligible, and if desired The positions of thethesaid air vent inay. 'be dispensed with- Consequently, with my presentmventlon, practically all the air necessary to effect the combustion ofthe fuel is drawn into the kiln by the draft. While I prefer to'make useof a pair of nozzles leading into each kiln, such an arrangement beingespecially advanta geouswit very long kilns, and particularly when thecom ustion zones overlap, as explained, it will be understood that aslngle nozzle may be employed and may be' advantageously used when the.kilns are relatively short.

Having-now described my invention, .what I claim as new and desire tosecure by Letters Patent, is as follows:

1. In a device of he character described,

the combination with a closed casing, a series of rotating vanes mountedin the casing,

said casing having a peri heral discharge 2. In a de ice for feedingpulverized'fuel,

a closed casing having a peripheral discharge opening, a, rotary membermounted within said casing and closely fitting the interior thereof inthe vicinity of said opening, means for rotating said rota member at ahigh speed, asupply bin, a c osed passageway between said bin and saidcasing, and aconveyer in said passageway, said passageway being providedwith a minute vent between the conveyer and said casing, substantiallyas described.

3. In a device of the character described, the combination of a kiln, asupply bin, a closed casing having a nozzle arranged to project fuelinto the kiln, a closed passageway connecting said bin and easing, acon.

veyer in said passageway for supplying fuel to said casing from saidbin, said passa .way being provided with a minute vent s tween theconveyer and said casing, and means in said casing adapted to dischargethe fuel wholly by impact through said nozzle andinto saidkiln,substantially as described. J

4. In a device of the character described, the combination of a kiln,mechanical means for projecting within and through one end of the kilnand solely by impact, a'continuous compact stream of pulverized fuelsubstantlally: free from admixed air, and a coolmg chamber communicatingwith the end 9f the kiln through which. the fuel is pro- Jected andsupplying air to the kiln where- .by the stream of fuel will be suppliedwith described.

vfrom admixed air, and means for su plying the stream of fuel asitenters the ki n with a surrounding envelop ,of air necessary to supportcombustion thereof, substantially as 6. In a device for feedingpulverized fuel,

a closed casing having a discharge opening,

a closed passageway communicating witl'n15 said casing, means forsupplying fuel to said casing through said passageway, and means withinsaid casing for discharging fuel therefrom through said dischargeopening,

said passageway being provided with a 20 minute vent, substantially asdescribed.

This specification signed and witnessed this 25th day of November 1907.-

THOS. A; EDISGN.

Witnesses:

FRANK L. Drnn, ANNA R. Krnmm Copies of this patent may be obtained forfive cents each, by addressing]; the Gomznissioner of Patents,

. Washington, D. E?

